As is known in the art, in data storage systems there is a desire to control the speed of the fan to limit the amount of noise and prolong the life of the fan. In previous systems the fan was allowed to run at full speed all of the time. Now, with fan speed control there is a device that monitors and controls the speed of the fan. However, there is the potential that the controller which provides the speed control signal to the fan might fail in such a way that it will cause the fan to stop spinning (i.e., a failure of the controller may produce a fan control signal of zero volts thereby resulting in the fan to stop spinning). Hence, if the controller stops functioning or loses power in such a manner that its control signal goes to 0 Volts, the fan will stop. The effect will unfortunately result in a rise in the temperature of the chassis and thereby require the system to be shut down.